The present invention relates to the formation of cast-in-place concrete slabs and, more particularly, is concerned with an improved apparatus and method for maintaining juxtaposed slabs in horizontal alignment, while accommodating their expansion and contraction and relative lateral movement. It is especially concerned with such a method and apparatus wherein a flat planar dowel is slidably received within a groove cut in an edge surface of a first slab and embedded within a second slab formed against the edge surface of the first slab.
The prior art teaches various types of dowels and load transferring devices for interposition between cast-in-place concrete slabs to maintain the slabs in alignment. These dowels and devices are cast-in-place during the formation of the slabs and require some type of mechanism to support them in place during the formation process. They may also include some type of spacer which is cast-in-place to accommodate limited movement of the slabs relative to one another.
The prior art also teaches the provision of cast-in-place dowels which are of a flat planer configuration and provided with a cast-in-place sheath to accommodate lateral movement of at least one of the slabs relative to the dowel. Such an arrangement may be seen in U.S. Pat. No. 6,534,760. It also requires some type of mechanism to support the dowel and sheath during the slab formation process.
It is also known to provide biscuit dowels for the joinder of wooden parts. Such dowels are of a flat planer configuration and are glued into grooves cut into the edges of the parts to be joined. U.S. Pat. Nos. 5,458,433 and 5,730,544 are exemplary of such devices. As contrasted to the dowel and load transferring devices used for cast-in-place concrete slabs, these dowels are securely adhered in place in both of the parts being joined.